Originally Posted by BillSeurer
The timer on the "main" quest in Fallout 1 did not prevent you from exploring the whole game because once you had restored the water to the vault you could then take your sweet time and spend in-game years if your wanted poking around the wilderness. And 100 days was a very long limit given how short Fallout 1 was anyway. I never hit the limit on any time I played FO1 and while not a "must open every container" guy I do tend to look most everywhere.

The main quest after finding the waterchip had a timelimit, though it was invisible. My first playthrough I hit that limit and mutants overran the vault and I had to go back to an earlier save in order to make the timelimit.